(1) Field of the Invention
This invention relates to novel and useful epoxy resin compositions having good adhesion properties, heat resistance and mechanical properties in combination. This invention is also concerned with novel epoxy resins obtained by reacting an epihalohydrin with an imido-ring-containing diphenol as an epoxy resin component and further with a process for the production thereof.
(2) Description of the Prior Art
Epoxy resins have been used widely as high-performance resins in a wide variety of products such as adhesives, paints, sealants and patching materials for their excellent mechanical and electrical properties and adhesion properties. Epoxy resins usable for these applications typically include 2,2-bis(4-hydroxyphenyl)propane, phenol novolak resin, o-cresol novolak resins, and those composed basically of polyfunctional epoxy resins derived from 4,4'-methylenedianiline, 4,4'-diaminodiphenyl sulfone or the like and an epihalohydrin. These epoxy resins have responded successfully to various performance demands in each field of application. They are also used in combination with a known curing agent and if necessary, with a curing accelerator, a filler and the like in the various application fields.
In recent years, the application of epoxy resins has however spread to advanced fields of technology such as high-performance composite materials and electronic materials in the space and aircraft industry and the like. Reflecting this, extremely high performance is required for matrix resins and adhesives in such advanced fields of technology. It is thus the present situation that the conventional epoxy resins can hardly satisfy such various performance demands.
In particular, there is almost no known epoxy resin composition which can satisfy all the performance demands required with respect to heat resistance, adhesion properties, mechanical strength, etc.